During a Class survey of a tanker, several cracks were found in the deck structure in the midship area, at the connection between the deck longitudinals and the deck openings (access and Butterworth hatches).

A Bulk Carrier was contracted to carry an occasional cargo of steel coils between two ports. When the vessel some time later discharged the cargo, it was noted that tank top plate had been indented. Internal inspection in the double bottom, below the cargo holds, revealed that longitudinals and floors had also been damaged.

During survey of cargo centre tanks, cracks were found in some of the deck longitudinals in a amidships. The cracks had penetrated through the flange, into the web of the deck longitudinal, and further into the deck plating at one location. The most probable cause of the cracking was fatigue due to longitudinal hull girder stresses combined with unfavourable location of welding in a knuckle.